Prolonged administration of human atrial natriuretic peptide in healthy men: evanescent effects on diuresis and natriuresis.

Synthetic human atrial natriuretic peptide (hANP) was administered to six normal sodium- and fluid-replete men A) as an iv bolus dose of 25 micrograms followed by an infusion of 25 micrograms/h for 6 h; B) as an iv bolus dose of 175 micrograms; C) as an iv bolus dose of 175 micrograms followed by an infusion of 100 micrograms/h for 6 h; or D) as a continuous infusion of 100 micrograms/h for 6 h plus an iv bolus dose at 240 min. Although urinary flow rates and excretion rates of sodium and chloride increased during protocols B, C, and D, this effect either disappeared (protocol B) or waned (protocols C and D) at the end of the 6-h infusion period. A consistent decrease in blood pressure occurred only during protocols C and D. Serum concentrations of Na+, K+, and Cl- and plasma renin concentrations did not change, while plasma aldosterone concentrations declined after the administration of 175 micrograms hANP or more. These data confirm that hANP exerts a diuretic and natriuretic action in man. These effects are transient and are not maintained by prolonged continuous hANP administration.